摘要 |
A stylus profilometer having a counterbalanced stylus with a motion transducer using a vane (41) moving between parallel, spaced-apart, conductive plates (35 and 37) which damp the motion of the vane by means of trapped air. The vane forms an electrode with the plates so that the combination is a pair of capacitors in a balanced bridge arrangement. Motion of the stylus causes an unbalance of the bridge indicative of the extent of stylus motion. A lever arm (59) associated with the stylus has a tip (57) influenced by a magnetic field which biases the stylus or controls force on a surface to be measured. The entire assembly has a very low moment of inertia to reduce the effects of vibration on the stylus and thereby increase resolution of the device and reduce damage to the substrate. |